1998 MITSUBISHI MONTERO fuel pressure

4) Using DVOM, check resistance across EVAP purge solenoid
terminals. If resistance is not 36-44 ohms at 68F (20C), replace
EVAP purge solenoid. Go to step 8). If resistance is as specified, go
to next step.
5) On 3000GT, go to next step. On Montero, disconnect EVAP
purge solenoid connector and MFI relay connector. Using DVOM, check
continuity between EVAP purge solenoid connector terminal No. 1 and
MFI relay connector terminal No. 1. If continuity does not exist,
repair wiring harness as necessary. If continuity exists, go to step
7).
6) Disconnect EVAP purge solenoid connector. Using DVOM,
check voltage between chassis ground and EVAP purge solenoid connector
terminal No. 1. If battery voltage does not exist, repair wiring
harness as necessary. If battery voltage exists, go to next step.
7) Turn ignition switch to OFF position. Disconnect PCM
connector. Ground PCM connector terminal No. 16. Using DVOM, check for
continuity between chassis ground and EVAP purge solenoid connector
terminal No. 2. If continuity does not exist, repair wiring harness as
necessary. If continuity exists, condition required to set DTC is not
present at this time. Go to next step.
8) Road test vehicle and attempt to duplicate conditions that
caused original complaint. Recheck for DTCs. If no DTCs are displayed,
test is complete.
DTC P0446: EVAPORATIVE (EVAP) EMISSION CONTROL SYSTEM VENT
CONTROL MALFUNCTION
NOTE: For terminal identification, see TERMINAL IDENTIFICATION. For
circuit and wire color identification, see
L - WIRING DIAGRAMS article.
1) Using scan tool, turn EVAP vent solenoid on and off (item
29). Listen for clicking sound from EVAP vent solenoid. If no sound is
heard, go to next step. If sound is heard, fault is intermittent. See
INTERMITTENT DTCS .
2) Disconnect EVAP vent solenoid connector and MFI relay
connector. Using DVOM, check continuity between EVAP vent solenoid
connector terminal No. 1 and MFI relay connector terminal No. 1. If
continuity does not exist, repair wiring harness as necessary. If
continuity exists, go to next step.
3) Turn ignition switch to OFF position. Disconnect PCM
connector. Ground PCM connector terminal No. 35. Using DVOM, check for
continuity between chassis ground and EVAP vent solenoid connector
terminal No. 2. If continuity does not exist, repair wiring harness as
necessary. If continuity exists, condition required to set DTC is not
present at this time. Go to next step.
4) Road test vehicle and attempt to duplicate conditions that
caused original complaint. Recheck for DTCs. If no DTCs are displayed,
test is complete.
DTC P0450: EVAPORATIVE (EVAP) EMISSION CONTROL SYSTEM
PRESSURE SENSOR MALFUNCTION
NOTE: For terminal identification, see TERMINAL IDENTIFICATION. For
circuit and wire color identification, see
L - WIRING DIAGRAMS article.
1) Using scan tool, check Fuel Tank Differential Pressure
(FTDP) sensor pressure (item 73). Pressure should be -0.48-0.48 psi.\
If pressure is not as specified, go to next step. If pressure is as
specified, fault is intermittent. See INTERMITTENT DTCS.
2) Remove fuel cap. Install a fuel tank filler tube adapter
in place of fuel cap. Connect a hand-held pressure/vacuum pump to fuel

tank filler adapter hose. Go to next step.
CAUTION: DO NOT apply more than 1.0 psi in following step. Applying
more than specified psi can crack fuel tank.
NOTE: Ensure fuel tank is at least 1/4 full. The lower the fuel
level in fuel tank, the longer it takes to pressurize fuel
system.
3) Apply 1.0 psi. Using scan tool, read Fuel Tank
Differential Pressure (FTDP) sensor (item 73). If scan tool reads mo\
re
than 0.86 psi, go to next step. If reading is 0.86 psi or less, fault
is intermittent. See INTERMITTENT DTCS.
4) Check On-Board Fuel Vent Valve (OFLV) for clogging. OFLV
is located in fuel tank filler tube assembly. If OFLV is clogged,
replace fuel tank filler tube assembly. Go to step 10). If OFLV is
okay, go to next step.
5) Check EVAP hoses, and purge and vent solenoids for
clogging. Repair or replace as necessary. Go to step 10). If hoses and
solenoids are okay, go to next step.
6) Disconnect FTDP connector. Ensure ignition is off. Using
DVOM, check for continuity between ground and FTDP sensor connector
terminal No. 2. If continuity does not exist, repair wiring harness as
necessary. If continuity exists, go to next step.
7) Disconnect PCM connector. Ground PCM connector terminal
No. 93. Using DVOM, check for continuity between chassis ground and
FTDP sensor connector terminal No. 1. If continuity does not exist,
repair wiring harness as necessary. If continuity exists, go to next
step.
8) Turn ignition on. Using DVOM, check voltage between ground
and FTDP sensor connector terminal No. 3. Voltage should be 4.8-5.2
volts. If voltage is not as specified, replace PCM. If voltage is as
specified, go to next step.
9) Inspect connectors and wiring harness between FTDP sensor
and PCM. Repair as necessary. If connectors and wiring harness are
okay, go to next step.
10) Road test vehicle and attempt to duplicate conditions
that caused original complaint. Recheck for DTCs. If no DTCs are
displayed, test is complete.
DTC P0455: EVAPORATIVE EMISSION (EVAP) CONTROL SYSTEM LARGE
LEAK DETECTED
NOTE: For terminal identification, see TERMINAL IDENTIFICATION. For
circuit and wire color identification, see
L - WIRING DIAGRAMS article.
1) Remove fuel cap. Push fuel pipe restrictor to operate On-
board Fuel Vent Valve (OFLV). Install and tighten fuel cap. Remove
fuel cap and ensure distance between filler tube and OFLV is 1.1" (28
mm). If distance is as specified, go to next step. If distance is not
as specified, replace fuel tank filler tube assembly. Go to step 20).
2) Disconnect and plug air filter-to-EVAP vent solenoid hose
at air filter. Disconnect intake manifold plenum-to-EVAP purge
solenoid at intake manifold plenum. Install a "T" fitting between
vacuum hose and intake manifold plenum. Connect a hand-held
pressure/vacuum pump to "T" fitting. Go to next step.
CAUTION: DO NOT apply more than 0.57 psi in following step. Applying
more than specified psi can crack fuel tank.
NOTE: Ensure fuel tank is at least 1/4 full. The lower the fuel
level in fuel tank, the longer it takes to pressurize fuel

system.
3) Using scan tool, read Fuel Tank Differential Pressure
(FTDP) sensor (item 73). Using hand-held pressure/vacuum pump, apply\
0.42 psi. If scan tool reading reaches 0.42 psi, go to next step. If
reading does not reach 0.42 psi, go to step 8).
4) Disconnect EVAP canister purge hose. Connect Purge Flow
Indicator (MB995061) between EVAP canister and disconnected hose. Turn\
engine on and allow it to reach operating temperature. Turn all lights
and accessories off. Place transmission in Park or Neutral. Observe
purge flow indicator while increasing engine RPM several times. If
purge flow indicator reads less than 2.5 SCFH (20 cm(3)/sec), check
EVAP canister purge hose and EVAP canister port for clogging. If hose
and port are okay, check EVAP purge solenoid. See DTC P0443. If
solenoid is okay, replace EVAP canister. Go to step 20).
5) Using scan tool, read Engine Coolant Temperature (ECT)
sensor temperature (item 21). Compare scan tool reading with
temperature gauge reading. If readings are about the same, go to next
step. If readings are not about the same, go to DTC P0115 test.
6) Using a thermometer, check engine compartment ambient
temperature. Using scan tool, read Intake Air Temperature (IAT) sensor\
temperature (item 13). Compare IAT sensor and thermometer readings. If\
readings are not about the same, go to DTC P0110 test. If readings are
about the same, go to next step.
7) Using scan tool, read Power Steering Pressure (PSP) switc\
h
status (item 27). Switch status should read ON when steering wheel is
turned. If switch status is as specified, go to step 20). If switch
status is not as specified, go to DTC P0551 test.
8) Remove fuel cap. Install a fuel tank filler tube adapter
in place of fuel cap. Plug fuel filler tube adapter hose. Disconnect
and plug air filter-to-EVAP vent solenoid hose at air filter.
Disconnect intake manifold plenum-to-EVAP purge solenoid at intake
manifold plenum. Install a "T" fitting between vacuum hose and intake
manifold plenum. Connect hand-held pressure/vacuum pump to "T"
fitting. Go to next step.
CAUTION: DO NOT apply more than 0.57 psi in following step. Applying
more than specified psi can crack fuel tank.
NOTE: Ensure fuel tank is at least 1/4 full. The lower the fuel
level in fuel tank, the longer it takes to pressurize fuel
system.
9) Using scan tool, read Fuel Tank Differential Pressure
(FTDP) sensor (item 73). Using hand-held pressure/vacuum pump, apply\
0.42 psi. If scan tool reading reaches 0.42 psi, replace fuel cap. Go
to step 20). If reading does not reach 0.42 psi, go to next step.
10) Disconnect hand-held pressure/vacuum pump from "T"
fitting. Install an evaporative emission system tester in place of
vacuum held pump and apply 0.49 psi. Wait two minutes. If pressure
drops less than 0.20 psi, go to next step. If pressure drops 0.29 psi
or more, go to step 13).
11) Disconnect EVAP purge solenoid-to-EVAP canister hose at
EVAP canister. Connect hand-held pressure/vacuum pump to hose and
apply 0.9 psi. If pressure is not maintained, check EVAP purge
solenoid for leak. If EVAP purge solenoid is okay, replace hose. Go to
step 24). If pressure is maintained, go to next step.
12) Disconnect EVAP vent solenoid-to-EVAP canister hose at
EVAP canister. Connect hand-held pressure/vacuum pump to hose and
apply 0.9 psi. If pressure is not maintained, check EVAP vent solenoid
for leak. If EVAP vent solenoid is okay, replace hose. Go to step 20).
If pressure is maintained, replace EVAP canister. Go to step 24).
13) Ensure hoses are properly routed and connected. See M -

VACUUM DIAGRAMS article. Install hoses as necessary and go to step
20). If hoses are okay, go to next step.
14) Disconnect OFLV-to-EVAP canister hose at OFLV and EVAP
canister. Plug hose at OFLV end. Connect hand-held pressure/vacuum
pump to hose at EVAP canister end. Apply 0.9 psi. If pressure is not
maintained, replace hose. Go to step 20). If pressure is maintained,
go to next step.
15) Using scan tool, read Fuel Tank Differential Pressure
(FTDP) sensor (item 73). Connect hand-held pressure/vacuum pump to
OFLV. While monitoring scan tool, apply 0.42 psi. If scan tool reading
reaches 0.42 psi, go to next step. If reading does not reach 0.42 psi,
go to step 19).
16) Disconnect OFLV-to-EVAP canister hose at EVAP canister.
Connect hand-held pressure/vacuum pump to hose and apply 0.9 psi. If
pressure is not maintained, go to next step. If pressure is
maintained, go to step 18).
17) Disconnect EVAP purge solenoid-to-EVAP canister hose at
EVAP canister. Connect hand-held pressure/vacuum pump to hose.
Disconnect intake manifold plenum-to-EVAP purge solenoid at intake
manifold plenum. Operate vacuum pump several times to apply vacuum. If
vacuum leaks, replace EVAP canister. Go to step 20). If vacuum does
not leak, repair clog in hose between EVAP canister and EVAP Purge
solenoid. Go to step 20).
18) Disconnect EVAP canister-to-OFLV hose at OFLV. If vacuum
does not leak, repair clog in hose between EVAP canister and OFLV. Go
to step 20). If vacuum leaks, check fuel tank filler tube assembly. If
fuel tank filler tube assembly is okay, repair clog in hose between
OFLV and fuel cut-off valve. Go to step 20).
19) Replace fuel tank filler tube and OFLV-to-fuel cut-off
valve hose. While monitoring scan tool, apply 0.42 psi with hand-held
pressure/vacuum pump. If scan tool reading does not reach 0.42 psi,
replace fuel tank. Go to next step.
20) Road test vehicle and attempt to duplicate conditions
that caused original complaint. Recheck for DTCs. If no DTCs are
displayed, test is complete.
DTC P0500: VEHICLE SPEED SENSOR (VSS) CIRCUIT FAILURE
NOTE: Speedometer testing procedures for 3000GT are not available
from manufacturer at time of publication. For terminal
identification, see TERMINAL IDENTIFICATION.
For circuit and wire color identification, see
L - WIRING DIAGRAMS article.
1) If using scan tool, go to step 4). On 3000GT, go to step
3). On Montero, speedometer testing procedures using DVOM require
removal of instrument panel. Removal and installation of instrument
panel is basically an unbolt and bolt-on procedure.
2) DO NOT disconnect connectors. Using DVOM, check continuity
between indicated speedometer terminals. See Fig. 40. Ensure
continuity pulses on and off with speedometer shaft revolution. If
continuity is not as specified, replace speedometer. If continuity is
as specified, go to next step.

specified, replace solenoid. If solenoid tests as specified, go to
next step.
4) Ensure solenoid holds vacuum with nipple "B" unplugged,
and negative jumper wire disconnected. If solenoid does not test as
specified, replace solenoid. If solenoid tests as specified, go to
next step.
5) Check resistance between solenoid terminals. If resistance
is not 36-44 ohms at 68
F (20C), replace solenoid. If resistance is
as specified, go to next step.
6) Remove turbocharger by-pass valve. Connect vacuum pump to
by-pass valve nipple. Apply 16 in. Hg of vacuum. Ensure vacuum holds
and valve begins to open. If by-pass valve does not test as specified,
replace by-pass valve. If by-pass valve tests as specified, go to step
8).
7) Turn ignition switch to ON position. Using scan tool, turn
turbocharger wastegate solenoid on and off (item 12). Clicking sound
should be heard. If clicking sound is not heard, go to next step. If
clicking sound is heard, go to step 10).
8) Disconnect solenoid connector. Turn ignition switch to ON
position. Using DVOM, check for voltage between chassis ground and
solenoid connector terminal No. 1. If battery voltage does not exist,
repair wiring harness as necessary. If battery voltage exists, go to
next step.
9) Turn ignition switch to OFF position. Disconnect PCM
connector. Ground PCM connector terminal No. 41. Check continuity
between chassis ground and solenoid connector terminal No. 2. If
continuity does not exist, repair wiring harness as necessary. If
continuity exists, go to next step.
10) Test is complete. Intermittent problem may exist. Road
test vehicle (if necessary) and attempt to duplicate conditions that
caused original complaint. Recheck for DTCs. If no DTCs are displayed,
go to INTERMITTENT DTCS .
DTC P1105: FUEL PRESSURE SOLENOID FAILURE
NOTE: This test applies to 3000GT turbo only. For terminal
identification, see TERMINAL IDENTIFICATION. For circuit and
wire color identification, see L - WIRING DIAGRAMS article.
1) If using scan tool, go to step 6). Remove vacuum hoses
from fuel pressure solenoid. Disconnect solenoid harness connector.
Connect a vacuum pump to solenoid nipple "A". See Fig. 47. Apply
vacuum and go to next step.
2) Using jumper wires, connect battery voltage and ground to
solenoid terminals. Ensure solenoid does not hold vacuum with nipple
"B" unplugged, and negative jumper wire disconnected. If solenoid does
not test as specified, replace solenoid. If solenoid tests as
specified, go to next step.
Fig. 47: Testing Fuel Pressure Solenoid
Courtesy of Mitsubishi Motor Sales of America
3) Ensure solenoid holds vacuum with nipple "B" plugged, and
negative jumper wire disconnected. If solenoid does not test as

specified, replace solenoid. If solenoid tests as specified, go to
next step.
4) Ensure solenoid holds vacuum with nipple "B" unplugged,
and negative jumper wire connected. If solenoid does not test as
specified, replace solenoid. If solenoid tests as specified, go to
next step.
5) Check resistance between solenoid terminals. If resistance
is not 36-44 ohms at 68
F (20C), replace solenoid. If resistance is
as specified, go to step 7).
6) Turn ignition switch to ON position. Using scan tool, turn
fuel pressure solenoid on and off (item 09). Clicking sound should be
heard. If clicking sound is heard, go to step 9). If clicking sound is
not heard, go to next step.
7) Disconnect fuel pressure solenoid connector. Using DVOM,
check for voltage between chassis ground and fuel pressure solenoid
terminal No. 1. If battery voltage does not exist, repair wiring
harness as necessary. If battery voltage exists, go to next step.
8) Turn ignition switch to OFF position. Disconnect PCM
connector. Ground PCM connector terminal No. 48. Check continuity
between chassis ground and fuel pressure solenoid connector terminal
No. 2. If continuity does not exist, repair wiring harness as
necessary. If continuity exists, go to next step.
9) Test is complete. Intermittent problem may exist. Road
test vehicle (if necessary) and attempt to duplicate conditions that
caused original complaint. Recheck for DTCs. If no DTCs are displayed,
go to INTERMITTENT DTCS .
DTC P1400: MANIFOLD DIFFERENTIAL PRESSURE (MDP) SENSOR
CIRCUIT FAILURE
NOTE: For terminal identification, see TERMINAL IDENTIFICATION. For
circuit and wire color identification, see
L - WIRING DIAGRAMS article.
1) Component testing procedure without using scan tool not
available from manufacturer at time of publication. Warm vehicle to
normal operating temperature and allow engine to idle. Go to next
step.
2) Using scan tool, read intake manifold pressure (item 95).\
See INTAKE MANIFOLD PRESSURE SPECIFICATIONS table. If scan tool does
not read as specified, replace MDP sensor. If scan tool reads as
specified, go to next step.
INTAKE MANIFOLD PRESSURE SPECIFICATIONS TABLE









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Application psi (kPa)
Montero .............................. 3.0-4.9 (20.6-34.0)
3000GT
DOHC
Non-Turbo ........................ 3.7-5.7 (25.5-38.9)
Turbo ............................ 4.2-6.2 (29.0-42.4)
SOHC ............................... 3.9-5.8 (26.5-39.9)









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3) Disconnect MDP sensor connector. Using DVOM, check
continuity between chassis ground and MDP sensor connector terminal
No. 2. If continuity does not exist, repair wiring harness as
necessary. If continuity exists, go to next step.
4) Turn ignition switch to OFF position. With MDP sensor
connector disconnected, disconnect PCM connector. Ground PCM connector
terminal No. 92. Check continuity between chassis ground and MDP
sensor connector terminal No. 1. If continuity does not exist, repair

* Check power supply to PCM.
* Check fuel pressure.
* Check ignition timing.
* Check for disconnected or damaged vacuum hoses.
* Check for control relay malfunction.
* Check for SFI system malfunction.
* Check for fuel pump drive control system malfunction.
* Check for ignition coil malfunction.
* Check for power transistor malfunction (if applicable).
* Check for fuel injector malfunction.
* Check for PCM malfunction.
* Ensure electrical harness, connectors and wires are not
broken, bent or loose.
ROUGH OR UNSTABLE IDLE
* Check intake air temperature sensor.
* Check EVAP purge control solenoid valve (if applicable).
* Check vehicle speed sensor.
* Check engine coolant temperature sensor.
* Check barometric pressure sensor (if applicable).
* Check manifold absolute pressure sensor (if applicable).
* Check ignition switch.
* Check throttle position sensor.
* Check camshaft position sensor.
* Check crankshaft position sensor.
* Check power steering oil pressure switch (if applicable).
* Check A/C switch and power relay (if applicable).
* Check park/neutral position switch (A/T).
* Check heated oxygen sensor.
* Check volume airflow sensor.
* Check fuel pressure.
* Check for disconnected or damaged vacuum hoses.
* Check for SFI system malfunction.
* Check idle air control (DC) motor (if applicable).
* Check idle air control (stepper) motor (if applicable).
* Check for fuel injector malfunction.
* Check for power transistor malfunction (if applicable).
* Check for vehicle speed sensor malfunction.
* Check for PCM malfunction.
* Ensure electrical harness, connectors and wires are not
broken, bent or loose.
ENGINE HESITATES OR POOR ACCELERATION
* Check intake air temperature sensor.
* Check engine coolant temperature sensor.
* Check barometric pressure sensor (if applicable).
* Check manifold absolute pressure sensor (if applicable).
* Check ignition switch.
* Check ignition coil.
* Check EGR control solenoid valve (if applicable).
* Check throttle position sensor.
* Check camshaft position sensor.
* Check crankshaft position sensor.
* Check power steering oil pressure switch (if applicable).
* Check A/C switch and power relay (if applicable).
* Check park/neutral position switch (A/T).
* Check heated oxygen sensor.
* Check volume airflow sensor.
* Check fuel pressure.
* Check for disconnected or damaged vacuum hoses.
* Check for SFI system malfunction.

* Check idle air control (DC) motor (if applicable).
* Check idle air control (stepper) motor (if applicable).
* Check for fuel injector malfunction.
* Check for power transistor malfunction (if applicable).
* Check A/C switch and power relay (if applicable).
* Check for PCM malfunction.
* Ensure electrical harness, connectors and wires are not
broken, bent or loose.
ENGINE SURGES
* Check engine coolant temperature sensor.
* Check EGR control solenoid valve (if applicable).
* Check fuel pressure.
* Check for fuel injector malfunction.
DETONATION OR KNOCKING
* Check for knock sensor malfunction (if applicable).
* Check volume airflow sensor.
* Check for engine cooling system problems.
* Check fuel quality.
* Check intake air temperature sensor.
* Check barometric pressure sensor (if applicable).
* Check manifold absolute pressure sensor (if applicable).
* Check ignition coil.
* Check power transistor (if applicable).
* Check for EGR system malfunction.
POOR FUEL MILEAGE
* Check intake air temperature sensor.
* Check engine coolant temperature sensor.
* Check barometric pressure sensor (if applicable).
* Check manifold absolute pressure sensor (if applicable).
* Check ignition switch.
* Check throttle position sensor.
* Check camshaft position sensor.
* Check crankshaft position sensor.
* Check power steering oil pressure switch (if applicable).
* Check A/C switch and power relay (if applicable).
* Check park/neutral position switch (A/T).
* Check heated oxygen sensor.
* Check volume airflow sensor.
* Check fuel pressure.
* Check for SFI system malfunction.
* Check idle air control (DC) motor (if applicable).
* Check idle air control (stepper) motor (if applicable).
* Check for fuel injector malfunction.
* Check for power transistor malfunction (if applicable).
INTERMITTENTS
INTERMITTENT PROBLEM DIAGNOSIS
Intermittent fault testing requires duplicating circuit or
component failure to identify problem. These procedures may lead to
computer setting a Diagnostic Trouble Code (DTC) which may help in
diagnosis.
If problem vehicle does not produce DTCs, monitor voltage or
resistance values using a DVOM while attempting to reproduce
conditions causing intermittent fault. A status change on DVOM